After its surprising election victory, Hamas is the new governing power among Palestinians. Now Israel and the U.S. have to consider dealing with a party they view as terrorists

He is an expert at plotting attacks against Israel. But now the chain-smoking Hamas military commander is trying to map out a different sort of plan: how to govern the Palestinians. The operative, a veteran of 16 years fighting Israel, met in the West Bank with other Hamas officials last week to celebrate the militant Islamic party's remarkable victory in Palestinian legislative elections and to figure out what in the world to do next. Dozens of meetings like that took place across the West Bank and Gaza Strip and even in Damascus, where Hamas has an office. Hamas leaders--suddenly thrust into...